Lab 4 - Algoritmi Geometrici

#include "graphics.h"
#include <math.h>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define pi 3.14

float x_1, x_2, y_1, y_2, alfa = 3.1415 / 8;
int xemax, yemax;
float theta = pi / 36.f; //unghiul de rotatie, in radiani
float xa, ya, xb, yb, xc, yc;//coord. Triunghiului

int xe(float x)
// normalizarea coordonatei x
{
    return((int)floor((x - x_1) / (x_2 - x_1)*xemax));
}
int ze(float z)
// normalizarea coordonatei y
{
    return((int)floor((y_2 - z) / (y_2 - y_1)*yemax));
}
void axe3D()
{
    setcolor(0);
    line(xe(x_1 / 2), ze(0), xe(x_2), ze(0));
    line(xe(0), ze(0), xe(0), ze(y_2));
    line(xe(0), ze(0), xe(0 + x_1 * cos(alfa)), ze(0 + x_1 * sin(alfa)));
    outtextxy(xe(0) - 15, ze(0) - 15, "O");
    outtextxy(xe(x_2) - 20, ze(0) - 20, "x");
    outtextxy(xe(x_2) - 6, ze(0) - 7, ">");
    outtextxy(xe(0) + 15, ze(y_2) + 5, "z");
    outtextxy(xe(0) - 1, ze(y_2) + 1, "^");
    outtextxy(xe(x_1*cos(alfa)), ze(x_1*sin(alfa)), "y");
}
void linie3D(float x0, float y0, float z0, float x, float y, float z)
{
    line(xe(x0 - y0 * cos(alfa)), ze(z0 - y0 * sin(alfa)),
        xe(x - y * cos(alfa)), ze(z - y * sin(alfa)));
}
typedef struct { float x, y, z; } punct;
punct G[50][50];

float f(float x, float y)
{
    //return (0.2*sin(x*x + y * y));
    //return (sqrt(16 - x * x - y * y));
    //return pow((4 * x / y), 2) + pow(z, 2) - 1;
    return (x * x - y * y);
}

void deseneazaSuprafata()
{
    int i, j, n;
    float h;
    h = fabs(x_1) / 25; //dimensiunea unui patrat mic
    n = 25; //numarul de linii ale gridului
    for (i = 0; i < n; i++) //constructia gridului
        for (j = 0; j < n; j++)
        {
            G[i][j].x = x_1 / 2.0 + i * h;
            G[i][j].y = x_1 / 2.0 + j * h;
            G[i][j].z = f(G[i][j].x, G[i][j].y);
        }
    setcolor(0); //desenare propriu-zisa
    for (j = 1; j < n; j++)
        for (i = 1; i < n; i++)
        {
            linie3D(G[i - 1][j].x, G[i - 1][j].y, G[i - 1][j].z, G[i][j].x,G[i][j].y, G[i][j].z);
            linie3D(G[i][j - 1].x, G[i][j - 1].y, G[i][j - 1].z, G[i][j].x,G[i][j].y, G[i][j].z);
        }
}
int main()
{
    printf("Limitele domeniului orizontal:\n");
    printf("x_1="); scanf("%f", &x_1);
    printf("x_2="); scanf("%f", &x_2);
    y_1 = x_1; y_2 = x_2;
    initwindow(800, 800, "Grafic suprafata: 2/10*sin(x^2+y^2)", 200, 200);
    xemax = getmaxx(); yemax = getmaxy();
    do {
        setbkcolor(14);
        cleardevice();
        axe3D();
        deseneazaSuprafata();

        for (int i = 0; i < 25; i++)
            for (int j = 0; j < 25; j++) {
                G[i][j].x = (G[i][j].x * cos(theta) + G[i][j].y * sin(theta));
                G[i][j].y = (G[i][j].y * (-sin(theta)) + G[i][j].y * cos(theta));
            }
        Sleep(100);
        theta += pi / 36.f;
    } while (theta <= 2 * pi);
    getchar(); getchar();
    closegraph();
    return 0;
}